There is known a printer, as an electrophotographic image forming apparatus, including a main casing, a drum unit, and a developing cartridge. The drum unit includes a photosensitive drum and is detachably mounted in the main casing. The developing cartridge is detachably mounted in the drum unit and includes a developing roller that supplies toner to the photosensitive drum. In this printer, the photosensitive drum and the developing roller are in contact with each other in a state where the developing cartridge is mounted in the drum unit.
In order to reduce a package size of such a printer at the time of transportation and shipment, for example, various methods have been proposed for transporting the printer in a state where the developing cartridge is mounted in the drum unit and the drum unit is accommodated in the main casing.
However, when the printer is transported in a state where the photosensitive drum and the developing roller are in contact with each other, such contact between the photosensitive drum and the developing roller may result in permanent deformation of the developing roller.
Thus, there has been proposed a printer provided with a separating member for separating a developing roller from a photosensitive drum. In this printer, the separating member is attached to a drum unit in which a developing cartridge is mounted.
Such a printer is transported in a state where the developing cartridge is mounted in the drum unit to which the separating member is attached and the drum unit is accommodated in a main casing. After transportation, the printer is installed at a predetermined installation place. The separating member is detached from the drum unit before the printer is used.